For four days residents of Los Angeles have -- their doors looked up the windows in the middle of the night. Fear of a serial arsonist who -- 55 fires burning cars and homes. But there is word tonight the police believe they have a person of interest under arrest. All thanks to a rookie cop and the surveillance tape ABC's David Wright is in Los Angeles with the news today David. Good evening Diane this is one of the carport set ablaze last night in here you can still smell the fumes. And multiply this scene by more than fifty you can see how this arson spree has terrorized these neighborhoods. Even though authorities now believe they have a suspect in custody there still running extra patrols and still urging residents to keep their lights on -- night. The prime suspect now charged with arson was arrested on Sunset Boulevard early this morning. Sources directly involved in the case tell ABC news one of the first things he said. Was I hate America it's got this big smile mistakes like he's the Joker -- something. A rookie sheriff's deputy was the first to spot the suspect driving a minivan with Canadian license plates. Matching the description of -- vehicle seen at some of the fires. Investigators tell ABC news -- search of the van turned up flammable materials matching what sparked the fires. Police also noticed that pony tail. Grainy images from security cameras showed a man and a pony tail to leaving a parking garage -- -- car was set on fire the driver. With -- -- and investigators with arson task force were notified. Subsequent interviewing this individual. He was placed under arrest a total of 55 fires since last week set in a five mile swath right up the middle of town. Including it does and -- fires overnight. So many blazes authorities weren't sure -- they were dealing with one fire bug where a series of copycats. Most started in car ports or garages some spread to nearby buildings before fire crews could get them under control. There's one big reason their confidence they have their man we have not responded to any fires since it is this individual was detained this morning just after 30. The big unanswered question is why. Sources tell ABC news the suspect's mother is about to be deported. Sources say he's a German national and his mother's deportation hearing took place a week and a half ago there's a number of reasons why. Individual set fires they do it out of spite of anger. The ATF just left this scene moments ago authorities still piecing together what may have provoked this arson spree all told more than emit more than two million dollars in damages. Thankfully no one killed but one firefighter was injured and one person suffered smoke inhalation.

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